Calculating Height With the Help of Sextant

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A sextant is a mechanical device for measuring the angle between two objects. Most commonly associated with navigation at sea, a sextant can also be used to help calculate the height of trees, buildings, flagpoles or any other vertical object.

 In ancient times, the navigator who was planning to sail out of sight of land would simply measure the altitude of Polaris as he left homeport, in today’s terms measuring the latitude of home port. To return after a long voyage, he needed only to sail north or south, as appropriate, to bring Polaris to the altitude of home port, then turn left or right as as appropriate and “sail down the latitude,” keeping Polaris at a constant angle.
The Arabs knew all about this technique. In early days, they used one or two fingers width, a thumb and little finger on an outstretched arm or an arrow held at arms length to sight the horizon at the lower end and Polaris at the upper.
The critical development was made independently and almost simultaneously by John Hadley in England and by Thomas Godfrey, a Philadelphia glazier, about 1731. The fundamental idea is to use of two mirrors to make a doubly reflecting instrument—the forerunner of the modern sextant.

 Choose an observation point from which you can clearly see both the top and the bottom of the object you wish to measure. Determine the exact distance between the observation point and the base of the object.

Set the sextant to zero and look at the object through the eyepiece, adjusting your view until it is in the center of the frame.

Adjust the sextant arm to split the screen in two halves. Continue moving the arm until the top half of the object on one side of the image is aligned with the bottom half of the object on the other side of the image.

Read the angle from the arc of the sextant.

Use a scientific calculator to find the height of the object by multiplying its distance from the observation point by the tan of the angle that you measured. For example, if you were 150 feet from the base of the object, and the recorded angle was 75 degrees, the height of the object would be 150 x tan 75 = 560 feet.

Remember to add the height you are holding the sextant above the ground to the total height of the object.

This video will help you:

Errors and Adjustments

The sextant is subject to a number of errors and adjustments. To find the true altitude of a celestial body from the observed these must be allowed and adjusted for.

Briefly these are:

  • Index Error
  • Dip
  • Refraction
  • Parallax
  • Semi-diameter

Index error is an instrumental error. When looking through a sextant at the horizon the exact level horizon will seldom be seen to be at 0°.

Sextant set at 0° – horizon split.Before every sextant session the Index error should be determined.

Index error corrected for – horizon level.

If the error is less than 0° it should be added to whatever reading is obtained – if more subtracted. Hint: remember Noah, if off the Ark – add, if on the Ark – take off.

Dip is an adjustment made for the height of the eye above sea level. In practice this is usually taken as 0.98 times the square root of the height of the eye in metres above sea level multiplied by 3.28.

Refraction is extracted from the Nautical Almanac. It allows for the “bending” of light rays as they travel through successive layers of varying density air.

Parallax corrections are needed if the observed body is a planet, the sun or the moon. From the Almanac.

Semi-diameter correction is needed if the observed body is the sun or the moon. In this case either the top or bottom of the celestial object (known as upper or lower limb) is made to touch the horizon. To obtain the centre of the body this correction is applied – from the Almanac.

Once all the corrections are applied we have the true altitude. And this subtracted from 90 gives us the zenithal distance to the sub-stellar point. Which means we know exactly how far we are from that elusive point on the earth which is at right angles to our observed celestial body!

Source(s):

Sciencing

Read here about the various uses of sextant

History of Sextant

Clipperlight

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Sunlust and Wanderlust in Tourism Motivation and Some Other Theories

Tourist motivation is seen by many writers as one of the key elements in understanding tourist decision-making. The big answer to the basic question, “why do people travel?” has occupied the minds of tourist researchers for many years. Various methods have been employed to uncover travel motives. The following literature will shed light on various theories that can be used to have a knowledge why people travel to urban destination.

Tourist motivation can be defined “as the global integrating network of biological and cultural forces which gives value and direction to travel choices, behaviour and experience.” (Pearce, Morrison & Rutledge, 1998).

Put simply, motivation is a state of arousal of a drive or need which impels people to activity in pursuit of goals. Once the goals have been achieved the need subsides and the individual returns to the equilibrium-but only briefly because new motives arise as the last one is satisfied. As cited in Seaton (1997) motivation of the individual person to travel, to look outside for what he cannot find inside have been largely created by society and shaped by everyday life. Gray’s (1979) travel-motivation theory, poses only two main motives for travel. One is the desire to go from a known to an unknown place, called in Gray’s theory “wanderlust”‘. The other motive is what Grays called “sunlust”. This generates a trip to a place which can provide the traveler with specific facilities that do not exist in his or her own place of residence. Some of the motives which determine their travel choices are recreation, pleasure, new experiences, cultural interest, shopping.

According to the ‘push’ and ‘pull’ concept, Crompton (1979), push factors explains the desire for travel while the pull motives have been used to explain the actual destination choice.  Nine motivations of leisure travelers were identified and classified seven as socio-psychological or push motives and two as cultural or pull motives. The seven push motives were, escape from a perceived mundane environment, exploration and evaluation of self, relaxation, prestige, regression, enhancement of kinship relationships, and facilitation of social interaction. The pull motives were novelty and education.

maslow-hierachy-of-needs-minMaslow (1943) identified two motivational types: tension-reducing motives; arousal-seeking motives. According to Maslow, there are five needs forming a hierarchy, progressing from the lower to the higher needs. At the bottom are the basic needs for food, water and air. Then, above them is the need for safety, security, and protection. Maslow argued that if the lower needs are fulfilled the individual would be motivated by needs of the next level of the hierarchy. Cooper et al (2005) criticises Maslow’s theory saying that why and how Maslow selected the basic five needs remain unclear, although Page (2003) feels that it has relevance in understanding how human action is understandable and predictable compared to research which argues that human behaviour is essentially irrational and unpredictable. Though much criticism about Maslow’s theory, the tourism industry has borrowed a lot from Maslow because he provides a convenient set of containers that can be relatively labeled and provide a useful framework for understanding psychological motivational factors in tourism. Thus, for example, although the apparent purpose of a trip may be for shopping, the underlying psychological motivation may be to impress their neighbours and gain higher social status. Iso-Ahola (1982) says that tourists will switch roles while on holiday, and that over time different needs will arise. Single motivation may not always act as the determining factor for travel. If within the holiday, the initial needs are satisfied, other motivations might emerge. Indeed, it is congruent with Maslow’s theories of needs to argue that if initially there is a primary need for relaxation while on a holiday, the satisfaction of that need will create awareness of other needs such as exploration of place as a means of acquiring a sense of belonging or to enable processes of self-actualisation to take place.

Dann (1981) has identified seven elements of tourist motivations: travel as a response to what is lacking yet desired; destination pull in response to motivational push; motivation as fantasy(engage in behaviour and activities that are culturally unacceptable in their home environment like prostitution and gambling); motivation as classified purpose(VFRs); motivational typologies; motivation and tourist experiences; motivation as auto-definition and meaning (the way in which tourist define their situations and respond to them).[Page & Connell,2003].

P.Pearce (1988) as cited in Ryan (1997) lists five travel motivations which he calls travel career ladder’ where tourists develop varying motivations of relaxation, stimulation, relationship, self-esteem and development, fulfillment. In Pearce’s model, the motivations listed can be divided into two categories. The needs may be self-centered or directed at others. Thus, for example, relaxation may be a solo exercise where the holiday-maker seeks a quiet restful time alone or it can be relaxation in the company of others, springing from the need for external excitement and desire for novelty. Stimulation can be self-directed which springs from the concern for own safety, or it can be directed toward others arising out of the concern for other’s safety. Relationship can be self-directed which means giving love and affection and maintaining relationships, or it can be directed at others which means receiving affection, to be with group membership. Self-esteem and development maybe self-directed like development of skills, special interests, competence and mastery, or it may be directed at others like prestige, glamour of travelling. Fulfilment is totally self-directed as it fulfils individual dreams, understands oneself more and experience inner peace and harmony. There are some criticisms against Pearce’s travel motivations. For example, Pearce argues that stimulation may be understood along a dimension of risk and safety of self or others. However, it might be argued that there is a real and distinctive difference between these two motivations.

Cohen (1972) as cited in Shaw & Williams (2002), draws attention to the fact that all tourists are seeking some element of novelty and strangeness while, at the same time, most also need to retain something familiar. How tourists combine the demands for novelty with familiarity can in turn be used to derive a typology. Cohen distinguished tourist using sociological principles into organised mass tourist, individual mass tourists, explorer and drifter. They feel that it is not based on any empirical data. In addition, these groups were also differentiated along the lines of contact with the tourist industry, with mass tourists being termed “institutionalised” and the more individualistic tourist being regarded as non-institutionalised.

Smith (1977) provided a more detailed variant of Cohen’s tourist typologies. Smith (1977) identifies 7 categories of tourist who have been termed as “interactional typologies”: explorer, elite, off-beat, unusual, incipient mass, mass, and charter.

Shaw & Williams (2002) opines that Plog’s typology is based on asking tourists about their real general “lifestyles” or value systems, often using perceptual information derived from interviews. Plog’s (1987) typology can be used to examine tourist motivations as well as attitudes to particular destinations and modes of travel. In terms of the latter, a tourist typology developed for the American Express (1989) has categorised travellers as: adventurers, worriers, dreamers, economisers and indulgers- all of whom viewed their travel experiences in different ways.

Source(s):

UK Essays

 

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Call for Papers 2019 MLA

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The Modern Language Association’s Forum on 20th- and 21st-century German literature is proposing a series of panels for the 2019 conference in Chicago that may be of interest to the readers of this blog. The series is entitled “Monuments and Monumentality. Museums, Media, Memory”.

Description:

In 2019, the Humboldt Forum is slated to open as a multiplex museum in the city castle, reconstructed as a monumental marker at the heart of Berlin. By virtue of its scale, this project joins a contested history of museums, monuments and counter-monuments, through which Germany has negotiated questions of patrimony from the nineteenth century to the twenty-first. This series of panels interrogates forms of monumentality across the media of film, literature, museums, and architecture, and asks how these have shaped the discourse on memory in turn.

How have curators, film and visual artists, writers, and architects in German-speaking Europe engaged with, countered, or reinforced…

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Gender Inequality: A Burning Issue In India

We  proud Indians of 21st century rise in celebrations when a boy is born, and if it is a girl, a muted or no celebrations is the norm. Love for a male child is so much so that from the times immemorial we are killing our daughters at birth or before birth, and if, fortunately, she is not killed we find various ways to discriminate against her throughout her life. Though our religious beliefs make women a goddess but we fail to recognize her as a human being first; we worship goddesses but we exploit girls. We are a society of people with double-standards as far as our attitude towards women is concerned; our thoughts and preaching are different than our actions. Let’s try to understand the phenomenon of gender inequality and search for some solutions.

Gender is a socio-cultural term referring socially defined roles and behaviors assigned to ‘males’ and ‘females’ in a given society; whereas, the term ‘sex’ is a biological and physiological phenomenon which defines man and woman. In its social, historical and cultural aspects, gender is a function of power relationship between men and women where men are considered superior to women. Therefore, gender may be understood as a man-made concept, while ‘sex’ is natural or biological characteristics of human beings.

Gender Inequality, in simple words, may be defined as discrimination against women based on their sex. Women are traditionally considered by the society as weaker sex. She has been accorded a subordinate position to men. She is exploited, degraded, violated and discriminated both in our homes and in outside world. This peculiar type of discrimination against women is prevalent everywhere in the world and more so in Indian society.

CAUSES AND TYPES OF GENDER INEQUALITY IN INDIA

The root cause of gender inequality in Indian society lies in its patriarchy system. According to the famous sociologists Sylvia Walby, patriarchy is “a system of social structure and practices in which men dominate, oppress and exploit women”. Women’s exploitation is an age old cultural phenomenon of Indian society. The system of patriarchy finds its validity and sanction in our religious beliefs, whether it is Hindu, Muslim or any other religion.

For instance, as per ancient Hindu law giver Manu: “Women are supposed to be in the custody of their father when they are children, they must be under the custody of their husband when married and under the custody of her son in old age or as widows. In no circumstances she should be allowed to assert herself independently”.

The above described position of women as per Manu is still the case in present modern day social structure. Barring few exceptions here and there, women have no power to take independent decisions either inside their homes or in outside world.

The unfortunate part of gender inequality in our society is that the women too, through, continued socio-cultural conditioning, have accepted their subordinate position to men. And they are also part and parcel of same patriarchal system.

Extreme poverty and lack of education are  reasons for women’s low status in society. Poverty and lack of education derives countless women to work in low paying domestic service, organized prostitution or as migrant laborers. Women are not only getting unequal pay for equal or more work but also they are being offered only low skill jobs for which lower wages are paid. This has become a major form of inequality on the basis of gender.

Educating girl child is still seen as a bad investment because she is bound to get married and leave her paternal home one day.Paucity of resources is also a reason for not sending girls to school, if a family have limited resources to spend on education , male child gets the preference, again because he is considered to be the better investment. in fact, it is not limited to girls, Parents do not see the usefulness of education , and so they,specially those who have meager resources,hesitate to send their child to school, but girls get a worse deal.

The only thing that parents understand is that their children will not get a job even if they graduate.Frighteningly they are often correct ,chances of being unemployed rises with education.

It’s a vicious cycle. Lack of skills translates into poverty and poverty forces the parents to place their children in bad schools.

Early marriage is a major impediment on the girl’s road to a meaningful education and/or a degree. The marriage blocks her education in most of the cases.

Thus, without having good education women are found lacking in present day’s demanding job market; whereas, each year’s High School and 10+2 standard results show that girls are always doing better than boys. This shows that parents are not spending much after 10+2 standard on girl child and that’s why they lack in job market.

Not only in education, in case of family food habits, it is the male child who gets more nutritious and choicest foods while the girl child gets whatever is left behind after the male members have taken their meals or the food which is low in both quality and nutrition. And this becomes a major health issue in her later years. One of the main reasons for the high incidences of difficult births and anemia in women is the poor quality of food which a girl always gets either in her paternal home or in her in-laws as also is the excessive workload that they are made to bear from their early childhood.

So the inequality or discrimination against women is at various levels in the society, either in home or outside home.

GENDER INEQUALITY IN INDIA: IMPORTANT DATA

Global Indices:

Gender Inequality is also reflected in India’s poor ranking in various global gender indices.

  • UNDP’s Gender Inequality Index- 2014: India’s ranking is 127 out of 152 countries in the List. This ranking is only above Afghanistan as far as SAARC countries are concerned.
  • World Economic Forum’s Global Gender Gap Index- 2014: India’s ranks at 114 in the list of 142 countries of the world. This Index examines gender gap in four major areas:
  • Economic participation and opportunity.
  • Educational achievements.
  • Health and life expectancy.
  • Political empowerment.

India’s position on these indicators was as follows:

  • Economic participation and opportunity: 134th
  • Educational achievements: 126th
  • Health and Life expectancy: 141st
  • Political empowerment: 15th

These two important Global Indices show the sorry state of affairs in India as far as gender equality is concerned. Only in case of ‘Political Empowerment’ India is doing fine which is a welcome sign. But other indices are very poor and a lot need to be done to improve the same.

GENDER INEQUALITY STATISTICS

Gender inequality manifests in varied ways. And as far as India is concerned the major indicators are as follows:

  • Female Foeticide
  • Female Infanticide
  • Child (0 to 6 age group) Sex Ratio: 919
  • Sex Ratio:943
  • Female literacy:46%
  • Maternal Mortality Rate:178 deaths per 100000 live births.

These above mentioned indicators are some of the important indices which show the status of women in our country.

Female foeticide and female infanticide are most inhuman of acts. And it is a shame that in India these practices are prevailing at large scale.

The data shows that despite the law in place viz Prenatal Diagnostic Techniques (Regulation and Prevention of Misuse) Act, 1994 sex selective abortion is still on the rise. One estimate done by MacPherson shows that more than 100000 illegal abortions are being performed every year in India mainly for the reason that the featus is of girl child.

Due to this, there is an alarming trend which has come to the notice in 2011 census report; the report shows Child Sex-Ratio (i.e sex-ratio of children between the age group 0 to 6) at 919 which is 8 points lesser than the 2001 data of 927. The data indicates that sex-selective abortion is increasing in our country.

As far as overall sex-ratio is concerned, it’s 943 in 2011 report as compared to 933 of 2001 which is 10 points increase. Though it is a good sign that overall sex ratio is increasing but it’s still tilted against females.

Female literacy is at 65.46% in 2011 as against 82.14% of male literacy. This gap indicates a wide gender disparity in India that Indians do not give enough importance to the education of girls.

All these indicators points towards the sorry state of affairs in India regarding gender justice and women’s human right. Though every year government starts various schemes and programs apart from existing ones for the benefit and empowerment of women but on the ground there are not enough visible changes. The change will appear only when the mind set of Indian society would change; when the society would start treating male and female on equal footing and when a girl would not be considered as a burden.

LEGAL AND CONSTITUTIONAL SAFEGUARDS AGAINST GENDER INEQUALITY

Indian Constitution provides for positive efforts to eliminate gender inequality; the Preamble to the Constitution talks about goals of achieving social, economic and political justice to everyone and to provide equality of status and of opportunity to all its citizens. Further, women have equal right to vote in our political system. Article 15 of the Constitution provides for prohibition of discrimination on grounds of sex also apart from other grounds such as religion, race, caste or place of birth. Article 15(3) authorizes the Sate to make any special provision for women and children. Moreover, the Directive Principles of State Policy also provides various provisions which are for the benefit of women and provides safeguards against discrimination.

Other than these Constitutional safeguards, various protective Legislations have also been passed by the Parliament to eliminate exploitation of women and to give them equal status in society. For instance, the Sati (Prevention) Act, 1987 was enacted to abolish and make punishable the inhuman custom of Sati; the Dowry Prohibition Act, 1961 to eliminate the practice of dowry; the Special Marriage Act, 1954 to give rightful status to married couples who marry inter-caste or inter-religion; Pre-Natal Diagnostic Techniques (Regulation and Prevention of Misuse) Bill (introduced in Parliament in 1991, passed in 1994 to stop female infanticide and many more such Acts. Furthermore, the Parliament time to time brings out amendments to existing laws in order to give protection to women according to the changing needs of the society, for instance, Section 304-B was added to the Indian Penal Code, 1860 to make dowry-death or bride-burning a specific offence punishable with maximum punishment of life imprisonment.

So there are varied legislative safeguards and protection mechanisms for women but the ground reality is very different. Despite all these provisions women are still being treated as second rate citizens in our country; men are treating them as an object to fulfill their carnal desires; crimes against women are at alarming stage; the practice of dowry is still widely prevalent; female infanticide is a norm in our homes.

HOW WE CAN ELIMINATE GENDER INEQUALITY

The list of legislations as well as types of discriminations or inequalities may go on but the real change will only come when the mentality of men will change; when the male species of human beings would start treating women as equal and not subordinate or weaker to them. In fact not only men but women also need to change their mindset as through cultural conditioning they have also become part of the same exploitative system of patriarchy and are playing a supportive role in furthering men’s agenda of dominating women.

Therefore, what is needed is the movement for Women’s empowerment where women can become economically independent and self-reliant; where they can fight their own fears and go out in the world fearless; where they can snatch their rights from the clutches of men and they don’t have to ask for them; where women have good education, good career, ownership of property and above all where they have freedom of choice and also the freedom to make their own decisions without the bondages of age old saying of Manu.

Let’s hope and wish that our participative democracy, in times to come, and with the efforts of both women and men, would be able to found solutions to the problem of gender inequality and would take us all towards our cherished dream of a truly modern society in both thought and action.

Source(s) and Link(s):

 http://www.indiacelebrating.com/social-issues/gender-inequality-in-india/

Zero Population Growth

 

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